This invention relates to an automatic temperature sensing switch, which serves also as a thermometer, for a room, a hothouse or greenhouse, or the like.
In prior art temperature controllers and switches, a thermometer has been provided, and mechanical means have been used for sensing the temperature indication of the thermometer, perhaps including electrical contacts or variable resistances. However, these prior art switches have had defects. The contacts and variable resistances have been prone to wear, and also the mechanical force of the sensing mechanical means on the thermometer indicator has often affected the temperature indicated by the thermometer, causing unacceptable inaccuracy. Especially in conditions of high humidity, and environments containing explosive and/or corrosive gases, such switches have been found wanting.